Recently, a magnetic optical recording reproducing system based on the Kerr effect has been developed, and it is desired to realize its practical use.
Intensive study to realize the practical use of the magnetic optical disk player has been made. The magnetic optical disk player is different from the conventional optical disk player. In the magnetic optical disk player, a relatively strong magnet for applying a bias magnetic field extends along the moving areas of a record/reproducing head and an erasing head.
In each head, an electromagnetic force is used for driving an objective to control a focusing servo system and a tracking servo system. Accordingly, the magnetic field for generating the electromagnetic force is adversely influenced by the bias magnetic field. This results in degradation of the servo response sensitivity of the head.